Turning trash into gas helps planet, pocketbook

When most San Joaquin County residents take out the trash, they'll also soon be turning on the lights across Northern California.

Alex Breitler

When most San Joaquin County residents take out the trash, they'll also soon be turning on the lights across Northern California.

Two major local landfills - one private, the other operated by the county - are within months of finishing new power plants that will take harmful methane gas created by the decomposition of garbage and convert it into electricity.

The plant at privately owned Forward Landfill southeast of Stockton will have a capacity of greater than 4.3 megawatts, enough to power about 4,380 average homes at any one time.

The other plant, at the county's Foothill Landfill near Linden, weighs in at 3.5 megawatts - roughly enough to power a city the size of Lathrop.

The projects were described as helping planet and pocketbook.

"Certainly, from an environmental perspective, we want to make sure we capture all the methane and use it in a resourceful way," said Kevin Basso, general manager of landfill owner Allied Waste. "And it makes sense economically."

Both landfills have entered into long-term agreements with the Massachusetts-based renewable energy company Ameresco, which is building the plants and will pay for the rights to the gas.

The power generated by Forward will go to Pacific Gas and Electric Co., while the county's power will go to the city of Palo Alto, which has its own electrical utility.

Desi Reno, the county's solid-waste manager, said he expects revenue from the power to generate an extra $600,000 to $900,000 per year to help pay for future waste needs in the county.

"It'll work out great," Reno said.

Most local residents produce trash that ultimately goes to Forward or Foothill. Lodi sends trash to the North County Landfill, however, which is not yet large enough to produce enough gas to justify a power plant there, Reno said.

Trash produces gas as it slowly decomposes in landfills. About half of that gas is methane, a greenhouse gas that is 21 times more potent than carbon dioxide. Landfills are the third-largest source of methane in the United States.

Rather than allowing methane to seep into the air, both landfills already collect the gas and burn it off in large flares.

The new power plants will allow them to put at least some of that gas to better use.

Some critics of landfill-based gas power plants in general have suggested such projects conflict with the goal of reducing the amount of garbage we dispose of in the first place. The Environmental Protection Agency, however, has said there is no conflict, because landfill power plants allow us to make something good out of the trash that has already been discarded while still striving to discard less overall.

The agency said there are already 621 landfill power plants in production in the country, including 78 in California.

According to an EPA database, the combined energy production of the county's two new power plants is enough to offset annual greenhouse gas emissions from more than 65,000 passenger cars or to offset the burning of more than 1,800 railcars full of coal.

The Forward plant should be online by November, with the Foothill plant following by the end of the year, officials said.